what are the 5 special senses?
smell , taste, vision, hearing, equilibrium
general senses receptor cells are what
modified dendritic endings of sensory neurons
special senses receptor cells convert a stimulus into electrical signals that reach the brain via what?
cranial nerves
chemical senses
detect chemicals in the external environment
olfactory cells
the receptors that respond to chemicals in the air
olfactory cells are unipolar bipolar or multipolar
bipolar
olfactory epithelium
lines the roof of the nasal cavity
to be smelled, an odorants molecules must be what
volatile (easily vaporized) and water soluble (so they can dissolve in the mucus layer coating the olfactory epithelium)
olfactory signals that travel through the cribiform go to where
the olfactory bulb
signals from the olfactory bulb travel to the brain along the what?
olfactory tract
the sense organ for taste
taste bud
taste buds contain what type of cells
gustatory cells and basal epithelial cells
where are taste buds located
on the papillae of the tongue
gustatory cells
modified epithelial cells that respond to chemicals in food and drink
signals from gustatory cells travel to the brain along sensory neurons in cranial nerve what?
VII, IX, X
purpose of saliva in gustation
dissolves substance to stimulate gustatory cells
basal epithelial are cells that produce what
new gustatory cells
what are the 5 primary tastes?
salt, sour, sweet, bitter, umami
umami is a subtle taste which seems to be responsible for what
the beef taste and characteristic tang of aging cheese
salt taste is produced by what ions
Na+ and k+
sour taste is produced by what acids
hydrogen ions
sweet and bitter tastes are produced by what
many different types of chemicals (most are organic)
what elicits sweet taste?
sugar, alcohol, some amino acids
some substances that taste bitter
alkaloids(caffeine) and long chain organic substances containing nitrogen
what elicits the umami taste?
aspartate and glutatmate (amino acids)
acid taste is indication of what?
rotting food
bitter taste is indication of what?
toxic substances
what are the sensory receptors for vision
rods and cones
rods and cones are located where
in the retina
vision receptors are what
neurons that respond to visible light
rods give a person ____ vision
black and white
cones give a person ____ vision
color
sensory input about vision reaches the brain via
cranial nerve II
concave lenses _____ light
diverge light (bend it outward)
convex lenses
converge light rays (bend them together)
what are the three small bones called?
auditory ossicles
fluid that fills the bony labyrinth
perilymph
fluid that fills the membranous labyrinth
endolymph
bony labirynth consists of what
cochlea, vestibule, semicircular canal
two parts of the cohlea
scala vestibule and scala tympani
the receptors for hearing and equilibrium are what
modified epithelial calls called hair cells
where are the hair cells of hearing found?
in the cochlear duct
where are the hair cells of equilibrium found?
utricle ,saccule, and semicircular ducts
the hair cells of equilibrium respond to what
changes in the position and movement of the head
sensory input about both hearing and equilibrium reach the brain via
cranial nerve VIII (8)
sensory adaptation
the decreased sensitivity of a sensory receptor to a sustained stimulus
conduction deafness
caused by poor transmission of sound waves
-sound does not reach inner ear
sensorineural deafness
-structures of the cochlea or the cochlear nerve do not function properly
visual acuity
sharpness of vision
astigmatism
caused by imperfections in the cornea
accomodation
increasing the lens refractive power
near point
the closes point at which an object can be brought into focus
why does it take longer to detect the taste of sugar on a dry tongue
saliva is needed to dissolve the particles to help with taste
what is the orientation of the image on the retina of the mechanical eye?
upside down and reversed
does the shape or size of the pupil have an effect on the field of vision?
does the shape or size of the pupil have an effect on the amount of light entering the mechanical eye?
no
yes
myopia (nearsightedness): cause and correction
eyeball is too long
-fix with a concave lense
hyperopia (farsightedness): cause and correction
eyeball too short
-convex lense
astigmatism: cause and correction
cornea uneven or wavy
-you need the opposite curves
your blindspot falls on what
your optic disk
why can a person with conduction deafness hear when the vibrating tuning fork is placed on his/her mastoid?
the temporal bones houses the inner ear so putting the fork on it vibrates the fluid within the inner ear moving the hairs in the inner ear
